Grate



Gams

Filed April 15, 1922 F. C. CRONBN ET AL HEM., E@ 924..

lll/ll Patented Dec. 16, 1924.

UNITED STATES PATENT oFFlcE.

FREDERICK C.y CRONIN AND JEROME A. HOFFMAN, OF DETROIT, MICHIGAN.

GRATE.

Application led April 15, 1922. Serial No. 552,855.

To all whom t may concer/h.:

Be it known that we, FREDERICK C. CRO- NIN and JEROME A. HOFFMAN, citizens of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Grates, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to grates for furnaces and hot fuel' burning stoves, boilers and other structures.

The primary object of our invention is to furnish a furnace with a grate o-n which very fine fuel may be burned and thus permit of low grades of coal, as screenings or mine wastes being used, without any danger to the grate or furnace, and without producing any defects in a heating apparatus. This is brought about by the manner in which air is admitted to a fire bed to insure a thorough combustion and an intense heat may be obi tained from such fine fuel thus permitting of the furnace being economically operated.

Another object of this invention is to provide grate members by which air gmay be distributed throughout a bed o-f fire or fuel to insure thorough -combustion and the manner of admitting air to the fire chamber tends to cool the grate and prevent warping or disintegration due to an intense heat.

A further object of ouriinvention is to provide simple and durable members through which air may pass to a combustion chamber "or Iire box and a body of air is maintained Iunder the grate members,q not only for cooling purposes but in order that the air may be preheated and thus placed in a better condition for combustion purposes.

A still further object of our invention is to provide grate members that may be used in connection with a furnace or heating apparatus operated with a forced draft, and

the grate members are constructed so thatl scribed by aid of the accompanying draw- Figure 1 is a ylongitudinal sectional View of a furnace in accordance with our invention; v

Fig. 2 is a horizontal sectional view of a portion of the same;

Fig. 3 is a. cross sectional view of a portion of the furnace;

Fig. 4 is an enlarged detail sectional view of a grate member showing air ports or jets or twyers, and f f Fig. 5 is a perspective viewlof a. detached grate member.

In the drawing, the reference numeral l denotes the greater portion of a furnace or heating apparatus which includes a combustion chamber or fire boX 2 having a doorway 3 permitting of fuel being placed in the combustion chamber 2 and clinkers or ashes removed therefrom. In the bottom of the furnace or heating apparatus is a chamber4 separated from the combustion chamber 2 by a plurality of grate members 5 suitably mounted in the furnace to form the bottom wall or floor of the combustion chamber 2 and a. ceiling or top wall of the chamber 4.

Extending into the Achamber 4 is an air supply pipe 6 through which air may be forced under pressure and said air supply pipe is located adjacent a side wall of the chamber 4 and is provided with air outlet flared nozzles 7 adapted to direct air against the lower faces of the grate members 5 or heat disseminating ribs 8 and tubes 10 on said grate members 5. rIhe ribs 8 and tubes 10 constitute heat radiating fins and the air contact-ing with the ribs, fins or tubes and the bottom faces of the grate members 5 will cool the grate members to a certain extent and in so doing absorb heat from said grate members and consequently be preheated. The air supply pipe 6 and its nozzles may supply sucient airfor the entire chamber, depending on its size, or such a pipe may be duplicated at the opposite side of the chamber 4. In either instance it is to be understood that there is sufiicient air for the purpose of our invention.

Each grate member may be rectangular, round, square or any suitable shape in plan and depending from the lower face of each member are a plurality of air conduits 9 having lower bell shaped or flared ends l0 permitting of air easily entering said conduits and since the conduits are carried by the grate member heat will be radiated thereby and air entering the conduits heated and placedin a. better condition fo-r conibustion purposes. v

The upper end of each conduit communicates with diverging or angularly disposed air outlet ports or jets or twye'rs 11 opening at the upper face of the member-5, it being preferable to circumferentially arrange or cluster the open ends of the ports or jets or twyers 11, as best shown in Fig. 5. The angularity of the ports or jets depends on the nature of fuel to be burned on the grate member` and also upon the heio'ht and area of the combustion space above t e grate and thickness of the fire bed to be maintained. For instance, if a fire bed of known depth is to be maintained in the combustion chamber the ports or jets or twyers 11 can be disposed at such angles that the ports or jets or twyers of one conduit will discharge currents of air that will intersect currents of air emitted by other or adjacent ports or jets or twyers with the inner section of said currents of air occurring at the top or surface of the fire bed. In this manner air will be supplied throughout the fire bed for combustion purposes, andit will be possible to burn a high percentage of the fuel placed on the grate members. When the fuel is in a finely divided condition the currents of air injected in the fuei will tend to open up the fuel to such anextent that all particles thereof will be either burned or subjected to an intense heat and there is no danger of any fuel packing or lying dormant on the grate members. In otherl words, a live bed of fuel will be maintained and an intense heat obtained therefrom.

Since air will be ejected from the ports or jets or twyers 11 there is no danger yof firmly powdered fuel clogging ports or jets or twyers, and it is apparent that the grate members may be made with the air outlet ports or jets or twyers so disposed as to produce the best results in connection with a solid fuel burning furnape or heating apparatus.

While in the drawing there is illustrated a preferred embodiment of our invention, it is to be understood that the construction is susceptible to such changes as are permisa relatively thin wall conduit having its upper end mounted in the lower face ofvsaid member and communicating with the lower yends of said diverging openings so that air may circulate aboutl said conduit and pass through said conduit and grate member.

3. In a heating apparatus, grate members, a chamber above said grate members in which a fire may be maintained, a chamber below said grate members adapted to receive air, dependmg conduit-s carried by said grate members within the air receiving chamber, said grate members having openings therein communicating with` said conduits and adapted to supply air to the fire chamber, and an air supply pine extending into the air chamber and adap'zed to direct air upwardly against the lower faces of the grate members.

4. In a heating apparatus, a fire chamber, an air receiving chamber, grate members separating said chambers, said grate members having groups of diverging openings therein adapted to distribute air in a fire -bed in the fire chamber, air heating conduits carried by said grate members and communicating with the openings thereof and extending into the air chamber, an air supply pipe adapted to supply air to said air chamber, and-nozzles carried by said air supply pipe and adapted to direct the air against said grate members and the conduits carried thereby.

5. As a new article of manufacture, a fuel supporting grate member having a relatively thick wall, provided with openings having the lower ends thereof terminating between the upper and lower faces of said member, and a bell-mouthed air inlet conduit solely supported by its upper end fitting in the lower face Iof said grate member, in communication with the lower ends of the openings of said member.

In testimony whereof we affix our signatures in presence of two witnesses.

FREDERICK C. CRONIN. JEROME A. HOFFMAN.

Witnesses: j

KARL H. BUTLER,

)HARLEs W. STAUFFIGER. 

